Engine-starting system



April 14, 1925.

' 1,533,104 C. H. DAVIS, JR

EriGINE STARTING SYSTEM Filed July 27, 1923 III! I mllmlm INVENTQR 0* (QM/M az f ATTOR EYS Patented Apr. 14, 19 25.

' UNITED STATES PATENT CHARLES HALL'DAVIS, 1a.,

QFFICE.

or rnrnnsnone, VIRGINIA.

ENGINE-STARTING- SYSTEM.

Application filed J'uly 27,

' gine-Starting Systems, of which the following is a specification.

My invention relates to starting mechanism or systems suitable for the mechanical cranking of internal combustion engines in motor vehicles and boats, and also useful in other adaptations-where some or allof the conditions are similar. l

The general object of the invent-ionis' to provide, in connection with an electric starting motor arranged for mechanical connection with a rotary part of the engine to start the same, a simple motor circuit which may be controlled by a single device to cause the motor to rotate and crank the engine, to provide means by which the controlling element will be ineffective to energize the starting motor when the engine is running, and in a preferred embodiment'of the invention to arrangethe circu't sothat it is closed for the energizing the starting motor by the movement of a controlling element normally employed for 'another purpose, which is preferably the clutch pedal-or an analogous controlling element of the power plant.

To accomplish the foregoing and other objects, the invention comprises, briefly described, any known or suitable starting motor arranged for mechanical connection to a moving part of the engine, this arrangement consisting, in a preferred example, of the Well-known 'Bendix drive mechanism in which a pinion'is automatically shifted when 40 the motor is energized and en ages 'a gear on the periphery of the engine y wheel, and then turnsthe flywheel at proper speed to" produce initial explosions 1n the engine cylinders, and thereupon the engine runs by'its .5 own energy at a speed somewhat greater. than the normal speedof the starting motor, which causes the starting pinion to be automatically shifted out of engagement with the fly wheel gear. Contacts are interposed 192s. Serial No. seams.

in the metor circuit, and'the clutch pedal of the motor vehicle or other equivalent controlling member of an engine installation, for instance, a clutch operating lever in a motor boat installation, is arranged to close the motor circuit when the pedal is depressed (or the lever is moved) to release the clutch. By this arrangement it is certain that the engine will be free from mechanical connection with the driven parts, such as the propeller of a boat or driving wheels of a. motor vehicle, when the engine is started, and at the same timethe starting of the engine is con-trolled by a lever on other controlling element which is necessarily employed for other purposes in the power plant installa- 5 tion. The system also includes suitable means for rendering theldepression of the clutch pedal or equivalent device ineffective to close the motor circuit when the engine is running, such means usually including a break in the motor circuit, with suitable fixed contacts and a movable contact arranged to close the break and complete the circuit whenthe engine is still, and to open the circuit "and prevent circuit closing by movement of the clutch pedal when the en gine is running at anything from about the predeterminedidling speed up to its maximum. The contact just mentioned is preferably controlled by some suitableautomatic so device, which is responsive to engine speed, so that the contact is automatically posi tioned for the stated purpose. The contact controlling device may be of the centrifugal governor type, or it may be a device actuated by pressure of oilin the engine lubricating system, or frictionally actuated by some rotary part of the engine; and in fact the circuit controlling mechanism may vary almost indefinitely in the broader aspect of the in? vention. The circuit breaker or contact device just mentioned with its controlling, mechanismmay'be identified conveniently as a circuit controller, or otherwise as an automatie switch or circuit breaker. The characteristics and advantages of the invention are further sufficiently explained in connection with the following detail deseription of the accom anying drawings, which show one exemplifying embodimentof the invention. After considering this embodiment, persons skilled in the art will understand that many variations may be made within the principles of the invention, and I contemplate the employment of any structure or combinations of parts which are properly within the scope of the appended claims.

Figure 1 is a side elevation of a typical motor vehicle power plant with the invention embodied therein or applied thereto in one form.

Figure 2 is a diagrammatic view showing the electric circuit and essential parts of the mechanism.

The particular mechanism chosen as a representative embodiment of the invention is adapted to an internal combustion engine 1 as ordinarily installed in a motor vehicle and having an electric starting motor 2, secured to the engine base 8. A pinion 4; on the motor armature is movable axially to engage with a gear 5 formed or secured on the engine fly wheel 6. While the pinion may be shifted to engage the fly wheel gear in different ways, or in fact, the starting motor may be connected to start the engine in any known or suitable fashion, the pinion 4: in the present example forms a part of starting mechanism of the well known Bendix type, in which the pinion is automatically shifted to engage the fly wheel gear when the motor armature commences to rotate by the closing of the motor circuit.

Any suitable change speed gearing 7 is located at any convenient position in the vehicle, in the present instance being connected to the engine base and forming a part of a so-called unit power plant comprising the engine, change-speed gearing (or transmission and a clutch contained in the housing 8 to connect and disconnect the engine with the driving Wheels of the vehicle through the transmission. The clutch is usually engaged by a spring and is released by depression of a clutch pedal lever 10 having a pedal pad 11 and mounted on a shaft 12. i

A storage battery 15 is provided as usual and a conductor 17 leads from the positive terminal of the battery to one terminal 18 of the starting motor; and a conductor 19 leads from the other motor terminal 20 back to the negative terminal of the battery.

Spaced contacts 22 are interposed at any suitable point in the motor circuit, in the .present instance, in the conductor 19, and

move between the contacts 22 and connect them, when the clutch pedal is depressed to a predetermined extent.

As so far described, whenever the clutch pedal is depressed to the predetermined extent, for instance, sufficiently to release the clutch and disconnect the engine from the vehicle wheels, a slight further movement of the pedal lever closes the motor circuit and the starter pinion 4 is thereupon thrown into engagement with the fly wheel gear and the engine is cranked, and as soon as it starts to run on its own power the starter pinion is automatically shifted away from the fly wheel gear, and the clutch pedal is thereupon released by the operator, the motor circuit is broken and the motor comes to rest. Since the clutch pedal is frequently depressed during operation of the vehicle to stop the vehicle or to permit gear shift ing. it is unnecessary and for many reasons undesirable to cause the starting motor to be energized at such times. Means are therefore provided to prevent energizing the starting motor when the engine is running. Such means may vary greatly and may include any automatic device actuated by the engine at any speed from about the normal minimum idling speed up to maximum speed of the engine, to prevent closing the motor circuit when the clutch is depressed. For example. such means may include another break in the motor circuit controlled by a contact which is positioned automatically by engine movement, for instance, the contact which bridges the gap may be in closed position to complete the circuit whenever the engine is still, and may be retracted to break the circuit, whenever the engine is running under its own power. As sufiiciently representing means of the class referred to, as shown in the drawings, spaced contacts are interposed in the circuit at any convenient point, for example, in the conductor 19, and a movable contact 31 is provided to bridge the gap between contacts 30, This movable contact may be in the form of a multi-leaf contact member to insure good contact without any substantial friction resistance. or any other suitable contact may be employed. The contact 31 is carried by an insulating member 32 on a lever 33 fulcrumed at 34, and the power arm yOf the lever is connected to the shiftable member 35 of any suitable governor 36, which is illustrated in this case as a centrifugal fiy-ball governor connected in any known or suitable way to any moving part of the engine, for instance; in the present example. the governor shaft 37 is connected by bevel gears 38 to an auxiliary engine shaft 39, which might be one of the cam shafts, or shown is an auxiliary shaft connected by suitable gearing 40 to the engine crank shaft 41 and employed also for driving some other engine auxiliary, such as the electric generator -42. Otherwise, the contact 31 might be moved by suitable mechanism controlled by pressure of oil in the engine lubricating system when the engine is running, by. air pressure caused by partial vacuum in the engine intake pipe, by hydraulic pressure in the engine cooling system, or by frictional cont-act with some engine.

' When a'centrifugal device is used as here shown, it may be the governor which is frequently employed on truck and other engines to regulate the engine speed. within certain limits.

rotary part of the The governor or other automatic circuit controlling member, or its connecting linkage, represented here by the lever 33, is adjusted so that contact 31 is positioned to close the circuit whenever the engine is at rest and remains so while the engine is rotating at cranking speed. As soon as the engine commences to run under its own power, however, it picks up speed consider ably and the automatic switch mechanism may therefore be so adjusted that as soon as cuit, which remains broken between the Contacts 30 until the engine again comes to rest; and then the circuit is reestablished in condition to be closed by depression of the clutch pedal.

In some instances the automatic switch or its controlling mechanism maybe adjusted so that the circuit will be broken between contacts 30 as soon as the engine speed exceeds to a stated extent the maximum speed at which it can be driven by the starting motor, and somewhat before the engine comes up toits normal idlihg speed. This adjustment or arrangement may be varied considerably, as will be sufficiently understood from preceding explanations.

The starting mechanism or system as above described embodies the following important advantages: The engine cannot be started while it is connected to the driving shaft or to an equivalent drivingmember of the power plant installation; there is no necessity for a separate starting device such as a lever or button intended only for starting purposes, and the operation of the vehicle or similar power plant installation is simplified because it is only necessary, whenever the engine is at rest, to depress the clutch pedal or equivalent controlling member of the installation, and thereupon the engine is started without attention to other devices; in a motor vehicle the first operation in getting under way is the depression of the clutch pedal preliminarycto placing the change speed gearing in an operative position, and this necessary operation at the same time accomplishes the starting of the engine; it follows from preceding statements that, in order to start the engine it must invariably first be disconnected from the vehicle driving shaft; the startin g of the motor is accomplished-by one foot Of the driver placed upon the clutch pedal and the other foot is free to manipulate the foot brake at the same time, whenever that is necessary, whereas in certain other systems a starting button or similar device tmust be operated by'one foot of; the driver; whenever the engine is running under its own power the starting circuit is automatically interrupted and it is impossible to energize the starting motor.

The automatic circuit controlling mechanism including the governor and movable and fixed contacts 30 and 31 may in some cases be arranged as a unit in a casing A and this may be secured to the engine base, as shown in Figure 1, in convenient position for alignment with shaft 39.. The governor or equivalent device may otherwise be arranged to be driven by or from other rotating parts of the engine.

I claim: 1. A starting system comprising an internal combustion engine, a member to be,

driven by the engine, a clutch interposed between the engine and said member, a clutch actuating lever, a starting motor, a source of electric energy, a circuit including the motor and said source of energy, a break in said circuit, a contact actuated by said clutch lever and positioned to close the circuit break when the clutch lever is moved beyond the clutch releasing position, means cuit to mechanically connect the starting motor with a rotatable part of the engine and crank the engine, another break in the motor circuit, and automatic switch mechanism including a contact which closes-said last-named circuit break when the engine is at rest, said switch mechanism being actuated by the engine and arranged to break the motor circuit at all engine speeds substantially greater than cranking speed.

2. In an automotive power plane installation, the combination with the engine, clutch, clutch lever, starting motor and 'mechanical cranking mechanism actuated by rotation'of the motor, battery and starting circuit including the battery, of starter control mechanism comprising a break in the motor circuit, a contact positioned by the ice clutch lever after movement to clutch releasing position to close the circuit and energize the motor, another break in the m0- tor circuit, and automatic switch mechanism impelled by the engine and serving to close said last named circuit break when the engine is at rest and to open the circuit at said break at all engine s eeds substantially greater than normal cran ing speed.

Signed at Petersburg, in the county of 1 'Dinwiddie and State of Virginia, this Qth day of July, A. D. 1923.

CHARLES HALL DAVIS. JR. 

